1. Field of the Invention
The present invention relates to a head suspension for supporting a magnetic head to read and write data in a hard disk drive.
2. Description of Related Art
The head suspension used for supporting a magnetic head in a hard disk drive generally has a base plate and a load beam. The base plate has a boss and supports the load beam that applies load onto the magnetic head.
The head suspension is attached to a carriage arm by joining the boss of the base plate to a hole of the carriage arm. The carriage arm is turnable around a spindle.
Correctly attaching the base plate to the carriage arm is very important for securing dynamic characteristics of the head suspension.
To correctly attach the head suspension to the carriage arm, Japanese Unexamined Patent Application Publication No. 2003-203448 teaches a head suspension having a base plate that includes a flange and a boss. The flange has a contact face to be brought in contact with a fitting face of a carriage arm. The boss is engaged with a hole of the carriage arm and is fixed thereto by plastic deformation when attaching the base plate to the carriage arm. At a corner between the boss and flange of the base plate, a recess is formed to define a gap with respect to the fitting face of the carriage arm.
This related art is capable of correctly attaching the contact face of the flange of the base plate to the fitting face of the carriage arm.
The related art, however, takes no account of a second face of the flange opposite to the contact face of the flange. The second face of the flange of the base plate is usually laid on a reinforcing plate as an auxiliary member and is fixed thereto by laser spot welding. At this time, if the second face of the flange is improperly aligned with the reinforcing plate, they will incorrectly be fixed together.